cat filename.txt |while read LINE
do
        echo $LINE
done
# LINE在這裡面只是隨便一個變數，並不是內建

或者

#!/bin/bash

while read aa
do
        echo $aa
done< filename.txt
#這種格式看起來更好

#!/bin/bash
myfile=filename.txt
count=0

cat $myfile |while read LINE
do
        echo $LINE
        let count=count+1
        echo $count line
done

[[email protected] prog]# cat filename.txt This is line number 1 This is line number 2 This is line number 3 This is line number 4 This is line number 5 This is line number 6 This is line number 7 This is line number 8 This is line number 9 This is line number 10